The present invention relates to a device for loading and unloading cable reels and the like from trucks, trailers or other supported beds. More particularly, the present invention relates to a reel handler device with a primary function of lifting and loading cable reels on to a truck bed or the like.
Reel handlers for loading and unloading reels from trucks or trailers are not new per se. Some reel handlers allow for powered payout and take-up of cable from the loaded reels by the use of friction rollers contacting the periphery of the reels. Examples are Hall, U.S. Pat. Nos. 3,184,082 and 3,325,118; and Woodruff, U.S. Pat. No. 4,228,967. Skalleberg et al U.S. Pat. No. 5,123,602 discloses a drive for cable reels by the use of frictional contact of the reel periphery with a powered car tire as the roller.
McVaugh, U.S. Pat. No. 3,820,673 allows for engagement of reels of varying sizes and permits transfer of one reel to a first location and return for a second reel. The assignee of that patent has a related U.S. Pat. No. 4,591,309. An improvement on this prior art is McVaugh U.S. Pat. No. 5,897,073, which has the advantage of using rugged motors and devices of relatively few moving parts to minimize damage and breakdown of the reel handler during use.
While that latter reel handler uses a compact, high torque, low speed hydraulic motor within its supporting reel arm to rotate the reel, there are some drawbacks to that design. Specifically, the angular travel or swing of the lift arms was less than preferred, and it was not seen to be possible to increasing the swing because of space constraints. In addition, mechanical losses at either end of the cylinder stroke became a concern. This patent uses mechanical “toggle links” between the lift arms and their lift hydraulic cylinders to achieve the angular swing of the lift arms, but they have a built in mechanical disadvantage.
Accordingly, it would be an advantage in the art if a reel loader could be provided with improved angular travel or swing.
Other advantages will appear hereinafter.